I agree that witnesses often get things wrong when questioned about events later.
Watch this short video:
http://www.youtube.com/watch?v=bioyh7Gnskg&NR=1
Yes. I flunked the test years ago when I first saw a version of this. It had a gorilla walking through the crowd of ballplayers.
I think it more likely that Earhart's idea of "on the next scheduled half-hour" was the next scheduled half hourly scheduled time, 8:00 am, just 2 minutes from her "now."
You can all make up your own minds about this.
Well, her language in an earlier message was "on the hour and the half-hour," so that "on the hour" would mean 8:00 AM and "on the scheduled half-hour" would mean 8:30. That WAS her announced schedule for listening, so it sounds to me as though she knew it was time for the 8:00 AM broadcast "now" and that she expected to be in the air 30 minutes later at 8:30. In other words, these messages make me think that she never said "I'm going down 30 minutes from now."
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To help us decide if Amelia actually said "half hour left" it would help if we knew if it were even possible for her to have burned that much gas in that time period. In looking at the various fuel consumptions we have assumed that Earhart flew at the correct speed and ran her engines so as to get the maximum possible range from the fuel on board. What if she didn't, would it have been possible for her to be down to a half hour of fuel at 1912 Z?
The calculations made in the past assumed a BSFC of .46 (Lockeed report 487) and nobody believes that she was able to get the .42 optimistic value in that report which was based on the requirement for her to fly a much longer leg to Tokyo. Nor was there any reason for her to try, since she should have had an abundance of fuel for the significantly shorter leg to Howland.
(BSFC means Brake Specific Fuel Consumption, pounds per hour per horsepower, the amount of fuel burned per hour for each horsepower being produced.) Since AVGAS weighs 6 pounds per gallon we can convert the 1100 gallons on board to 6600 pounds for this calculation. With a BSFC of .46 pounds per hour per horsepower, burning one gallon per hour will produce 13 horsepower. With this shortcut you can just divide the power output by 13 to find the gallons of fuel consumed per hour. Using this BSFC makes it appear that there was no way for her to use up all the fuel so quickly. The trouble with assuming that she operated with that BSFC is that you can only adjust the engines' mixture controls to lean the mixture out the achieve that BSFC at lower power settings and at high power settings you need to run the engines at "full rich" and then the engines burn fuel at a higher rate so the BSFC goes up. Air cooled aircraft engines use this extra fuel flow to dissipate the high heat being produced at high power settings and this extra fuel is not burned and does not produce any extra power.
I have the power setting table from Pratt and Whitney for the S3H1.
According to Pratt and Whitney, each engine burns 65 gallons per hour at the full 600 hp power output making the BSFC .65. (65 X 6 /600 = 65), a total of 130 gallons per hour. Running the engines at full power would have used up the 1100 gallons on board in 8:28 and if only 1050 gallons were on board in only 8:05. But you are allowed to run at 600 HP for only 5 minutes.
Running the engines at 550 hp burns 55 gallons per hour (each side, 110 gph total) making the BSFC .60 and
burning all the 1100 gallons in ten hours causing the engines to fail at 1000 Z so she could have run out of fuel 10 hours and 13 minutes prior to her last transmission. If she departed with only 1050 the engines would have quit at 0933 Z.
Contrary to Lockheed report 487 and other documents that state the BSFC of .42, the best BSFC obtained according to this Pratt and Whitney (the people who manufactured the engines) table is .48 and this was at 300 and 350 hp. Cruising with 350 hp per engine burns 28 gallons per hour per engine which would have used 1100 gallons in 19 hours and 38 minutes and 1050 gallons in 18 hours and 45 minutes. Cruising with 300 hp per engine uses the 1100 gallons in 22:56 and 1050 gallons in 21:52.
So the answer to the question is
YES, it
is possible for Earhart to have opperated her engines in such a way as to have consumed all of the fuel in that short period of time.
gl